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Lines from Donald Trump Jr.'s speech repeated lines from a Frank Buckley column that ran in May

Buckley was a contributor to Trump Jr.'s speech, he said

Cleveland (CNN)For the second night in a row, a successful speech by a family member of Donald Trump was overshadowed by questions of plagiarism. But on Tuesday night, the speechwriter in question quickly defended the real estate mogul's family.

Donald Trump Jr.'s speech brought down the house, standing out as one of the highlights of the program on the night he also announced his father had the votes to capture the GOP nomination.

But a tweet from "The Daily Show" shortly after the speakers for the night wrapped up pointed out two sentences in Trump's speech that appeared essentially verbatim in a May column by conservative writer Frank Buckley in "The American Conservative."

He then told CNN: "I was a principal speechwriter for the speech. So it's not an issue."

Trump Jr. had said: "Our schools used to be an elevator to the middle class. Now they're stalled on the ground floor. They're like Soviet area department stores that are run for the benefit of the clerks and not the customers, for the teachers and the administrators and not the students."

That matched Buckley's writing: "What should be an elevator to the upper class is stalled on the ground floor," Buckley wrote. He latter added: "Our schools and universities are like the old Soviet department stores whose mission was to serve the interests of the sales clerks and not the customers."

Buckley did not immediately respond to a question about whether Trump Jr. knew about the recycled lines.

Tuesday night, Donald Trump's spokesman tweeted that the campaign saw no issue with the speech and blamed the Hillary Clinton team for raising the accusations -- although there was no evidence to link Clinton to the controversy.

"Nice try Clinton machine -- Francis Buckley is a friend of Don Jr.'s and worked with him on the speech," senior campaign communications aide Jason Miller tweeted. "Your time would be better spent searching for Crooked Hillary's missing emails rather than disparaging a real American Patriot."

1/2 Nice try Clinton machine -- Francis Buckley is a friend of Don Jr.'s and worked with him on the speech.